The age-standardized incidence of acute MI decreased from 176.1 cases/100,000 people before the ban to 152.4 cases/100,000 after implementation of the ban. The 13% reduction was statistically significant (rate ratio, 0.87; 95% CI, 0.84–0.90). Smoking prevalence in Saskatoon decreased from 24.1% in 2003 to 18.2% in 2005 but was unchanged in the province of Saskatchewan.
The study contained some information available from a survey that determined changes in active smoking status (for example, a decrease in the number of people who actively smoked and a decrease in the number of cigarettes smoked by the people who continued to smoke). In addition, the study had a large sample and comprehensive data. The study accounted for changes in ICD coding for acute MI, choosing its timeframe on the basis, in part, of the coding change. The study has a number of limitations: no information on individual exposure to secondhand smoke was available, the postimplementation study period was brief, and no comparison city was available to permit assessment of trends or of any long-term decline.
Scotland prohibited smoking in enclosed public places and workplaces—including bars, restaurants, and cafes—as of March 2006. As described by Haw and Gruer (2007), the exceptions included “residential accommodation and designated rooms in hotels, care homes, hospices, and psychiatric units.” Pell et al. (2008) conducted the only study that assessed the effects of that ban on acute coronary events. The study surveyed participants on smoking status and secondhand-smoke exposure before and after the ban, and it measured serum cotinine. The correlation between self-reported duration of exposure to secondhand smoke and serum cotinine concentrations was similar before (r = 0.33, p < 0.001) and after (r = 0.33, p < 0.001) the implementation of the smoking ban. The number of never-smokers who reported no exposure to smoke increased from 57% before the ban to 78% after implementation (p < 0.001) largely because of reduced exposure to smoke in pubs, bars, and clubs. The geometric mean of individual serum cotinine measurements in never-smokers decreased from 0.68 to 0.56 ng/mL (p < 0.001) after implementation. Participants identified as former smokers showed similar changes before and after implementation. Those data indicate that secondhand-smoke exposure decreased in the study population after implementation.
Other published research supports the conclusion that secondhand-smoke exposure decreased in Scotland after implementation of the ban. Semple et al. (2007a) monitored PM2.5 during 53 visits to 41 pubs in